Aldabra Giant Tortoise

Discover the fascinating world of aldabra giant tortoises! From their varied species to their place in the Testudinidae family, learn everything you need to know about these reptiles.

Introduction To Aldabra Giant Tortoise

Aldabra is an island group in the Indian Ocean and the giant tortoise live in the Aldabra atoll, so Its name derives from its habitat. The Aldabra Atoll is part of the Seychelles in die Indian Ocean and the Aldabra Giant Tortoise is a large reptile found on the Aldabra Atoll in Seychelles. An atoll is a ring-shaped coral reef, island, or series of islets. The habitat inside the atoll, protected from the open sea by the sturdy reef, is called a lagoon. Sometimes, atolls and lagoons protect a central island. The tortoise can grow to be over two meters long and weigh up to 250 kilograms. The Aldabra Giant Tortoise has a massive defensive shell known as a carapace that protects the vulnerable, soft body within. These animals are terrestrial and inhabit a wide range of habitats, including mangrove swamps, scrub forests, and coastal beaches and dunes. The Aldabra Giant Tortoise mainly dwells in the grassy and swampy regions of the Aldabra Atoll. They are found both individually and in herds, which tend to gather mostly on open grasslands. The tortoise is unique because it is the only extant species in its genus, Alderbia.

Common Name

Aldabra tortoise, Giant tortoise

Scientific Name

Aldabrachelys gigantea

Size

3-4 feet

Weight

159-250 kg

Average Life Span

80-120 years

Group(s)

Scientific Name Of Aldabra Giant Tortoise

The Aldabra giant tortoise is a species of tortoise in the family Testudinidae. The species is endemic to the Seychelles, with the nominate subspecies, A. g. gigantea native to Aldabra atoll. It is one of the largest tortoises in the world. The scientific name for the Aldabra Giant Tortoise is "Aldabrachelys gigantea or Geochelone gigantea". They are native to Aldabra Island, one of the Seychelles northeast of Madagascar in the Indian Ocean.

Facts And Features About Aldabra Giant Tortoise

The Aldabra giant tortoise is one of the most interesting creatures on earth. Here are some incredible facts and features about this amazing creature:

  1. The Aldabra giant tortoises can weigh up to 500 pounds and live for over 100 years. They have a massive defensive shell known as a carapace that protects the vulnerable, soft body within.
  2. Their shells are typically beautiful brown or black with dark spots for males while females are lighter in colour. Their skin is also very colourful with shades of yellow, green and blue being common.
  3. These giant tortoises also have long necks and legs which makes them very graceful animals. 
  4. Another interesting fact about Aldabra giant tortoises is that they can swim and hold their breath underwater for up to 30 minutes, this means they can travel between islands if they need to.
  5. They also have very strong jaws which they use to crush hard nuts and other food items.
  6. The Aldabra giant tortoises are the only species of tortoise that can exist completely underwater for up to 5 minutes. They have a small hole on the top of their head called a fontanelle that allows them to breathe when their head is underwater. 
  7. They are also one of the most sexually dimorphic of all vertebrates, with males being around twice as large as females. Females lay clutches of eggs weighing up to 5 kg (11 lb) which they incubate for up to 8 months.
  8. Aldabra giant tortoises consume so much vegetation that they can change the appearance of an island over time by removing large amounts of foliage.
  9. Their favourite prey items include prickly pear cactus, hibiscus flowers and coconuts. They can go without food or water for long periods.
  10. Tortoises are considered as reptiles and not amphibians because they are vertebrates that is they have a backbone. They are covered in scales. They breathe through the lungs.

Appearance And Anatomy Of Aldabra Giant Tortoise

Aldabra giant tortoise is a species of large, herbivorous tortoise endemic to the Aldabra Atoll in Seychelles. It is the largest living species of tortoise and the second-largest reptile in the world, after the saltwater crocodile. The head is relatively small and blunt with a wide mouth that opens into a long neck. Their shells are light brown or tan with dark blotches and their skin is pale yellow. Their eyes and nostrils are located on the top of their heads. They have powerful thick legs and webbed feet. They have strong jaws and small air chambers inside their shells that help hold up their massive bodies. The carapace is high and convex, with prominent ridges on each scute. The plastron is small and flat, with two hinges that allow the animal to close its shell completely.

Their eyes and nostrils are located on the top of their heads, so they can breathe and see while they’re submerged in water. They have powerful legs and webbed feet which help them move through the water quickly and they use their strong jaws to crush hard fruits and vegetables. Aldabra giant tortoises have large dome-shaped shells to protect the delicate bodies that lie beneath their shells. Males are considerably larger than females and have longer, thicker tails.  An adult Aldabra giant tortoise can weigh up to 250kg and measure 4.3 ft long. The male's carapace length can measure 4 ft and they can weigh up to 250 kg. The female's carapace can measure 3 feet and can weigh 159 kilograms.

Habitat And Distribution Of Aldabra Giant Tortoise

It is the world's largest living tortoise and the second-largest species of tortoise after the Galapagos giant tortoise. These tortoises enjoy a variety of habitats like coastal beaches, coastal dunes, grasslands, mangrove swamps, and scrub forests. There are two main types of tortoise:

  1. Domed tortoises, which live in the cooler regions of the archipelago and
  2. Saddle-backed tortoises, which live in dry, coastal environments.

The Aldabra giant tortoise is distributed across three islands in Seychelles, Grand Terre, Picard Island and Denis Island. They are found on Aldabra Island, one of the Seychelles northeast of Madagascar in the Indian Ocean. Aldabra Islands, atoll, one of the world's largest, in the Indian Ocean about 600 miles (1,000 km) southwest of the Seychelles group and part of the Republic of Seychelles. They were introduced to Mauritius and the Reunion Islands. Aldabra Island is a coral atoll (An atoll surrounds a body of water called a lagoon) bordered by jagged limestone and small beaches and encloses a large mangrove-bordered lagoon.

Common Types Or Subspecies, Characteristics And Examples Of Habitats

There are four subspecies of Aldabra tortoises:

  1. Aldabra tortoise
  2. Seychelles giant tortoise
  3. Arnold's tortoise and
  4. Hololissa

The Aldabra giant tortoise is the most common giant tortoise. The main population of the Aldabra giant tortoise resides on the islands of the Aldabra Atoll in Seychelles. The atoll has been protected from human influence and is home to some 100,000 giant tortoises, the world's largest population of animals.

Aldabra tortoises' have a massive defensive shell known as a carapace that protects the vulnerable, soft body within. Their carapace (upper shell) has a small neck plate that is usually visible, a feature absent in other species of giant tortoises. The males have a concave plastron (belly shell) that aids in mating. They are dark grey to black with a highly domed, thick carapace. Their back legs are thick and somewhat resemble the legs of an elephant. The front legs, on the other hand, are rather flat and covered with large scales. Their toes have no webbing between them, and many species have five claws on each front foot.

Aldabra Island which is a group of islands in the Indian Ocean Is the common habitat of the Aldabra Giant Tortoise. It is a marine habitat that ranges from coral reefs to seagrass beds and mangrove mudflats with minimal human impact. The property is an outstanding example of an oceanic island ecosystem in which evolutionary processes are active within a rich biota.

Diet And Prey Of Aldabra Giant Tortoise

The Aldabra giant tortoise is a herbivore that feeds mainly on leaves, flowers, fruits, grasses and cacti. They have also been known to eat invertebrates, such as insects, snails, worms, crabs and lizards but this does not make up the majority of their diet. They will eat meat when it is available and possibly even eat the carcasses of dead tortoises. They typically have a slow metabolism, so they can digest tough plants easily. Their strong jaws also help them to crush through the hard shells of fruits. They consume so much vegetation that they can change the appearance of an island over time by removing large amounts of foliage. Some of their favourite prey items include prickly pear cactus, hibiscus flowers and coconuts. They can go without food or water for long periods. They are grazers and browsers, feeding mainly on grasses and woody plants.

Behaviour And Lifestyle Of Aldabra Giant Tortoise

The giant tortoises are generally shy animals but they can be very aggressive when threatened. They can defend themselves by using their powerful jaws and sharp claws. While they are characteristically slow and cautious, they are capable of appreciable speed. They are also known to attempt perilous acrobatic feats, rising precariously on their hind legs to reach low branches. Tortoises have also been known to ram intruders with their shells. They are diurnal animals, spending most of their day time foraging for food resting in the shade or swimming in the ocean when not grazing.

They live in social groups with males occupying territories that overlap those of several females and often from small herds of 5-10 animals. Aldabra Giant Tortoises are most active in the mornings when they spend time browsing for food. They dig underground burrows or rest in swamps to keep cool during the heat of the day. They can survive for long periods without food or water and they can go without eating for up to a year and can survive for up to two weeks without water. These animals can be very aggressive towards members of their species, biting and roaming each other in territorial disputes. They risk death by tipping onto their backs and being unable to right themselves. This unusual behaviour led Mexican biologist José Antonio de Alzate y Ramírez to refer to the Aldabra as the "ninjas" of the tortoise world.

Reproduction, Babies And Lifecycles Of Aldabra Giant Tortoise

The tortoise is a critically endangered species with a unique life cycle. Aldabra Giant tortoises reproduce slowly, making their populations particularly vulnerable to extinction. Female Aldabra giant tortoises lay eggs once every 2 to 4 years and the eggs take 8 to 10 months to hatch. When they do hatch, the baby tortoises are just a few inches long and weigh less than 1 pound. They spend the first few years of their lives eating leaves and grasses, growing slowly until they reach sexual maturity at around 20 years old. At that point, they start looking for a mate and can live for another 50 or 60 years. The lifespan of an Aldabra giant tortoise ranges from 80 – 120 years. However, it can extend up to 150-200 years.

Predators And Threats Of Aldabra Giant Tortoise

Despite their size, these tortoises have been preyed upon by several predators. The primary predators are humans, dogs and cats, including feral pigs, rats and sharks. In addition, their eggs have also been preyed upon by monitor lizards, snakes and birds. These turtles are also threatened by habitat loss, degradation and climate change. Their natural habitat is being destroyed by human development which is causing them to lose their traditional nesting grounds and food sources.

Population Of Aldabra Giant Tortoise

The Aldabra giant tortoise is the largest extant tortoise in the world and one of the oldest living reptiles. These gentle giants are found only on the Aldabra Atoll, a group of islands in the Indian Ocean. The Aldabra giant tortoise (Aldabrachelys gigantea or Geochelone gigantea) has received modest protection. As a result, it has attained a total population of more than 100,000 according to some estimates, with densities in some areas of 30 to 160 individuals per hectare and there are 150,000-200,000 Aldabra Giant Tortoises left in the world. Aldabra giant tortoises are endemic and critically endangered due to habitat loss, degradation, introduced predators (e.g., rats, dogs, cats) and poaching for food and trade.

Importance Of Aldabra Giant Tortoise

Aldabra giant tortoise plays an important role in the ecosystem.

  1. It alters the habitat when its vigorous searches for food fall trees and creates new pathways and clearings that are beneficial for other animals.
  2. It also plays an important role in the dispersal of seeds. The giant tortoises can modify the vegetation structure and create habitat heterogeneity and can even structure the population biology or the trait evolution of plant species.
  3. These tortoises provide important habitat spaces for smaller animals and insects within their burrows.
  4. As the largest animal in its environment, the Aldabra tortoise performs a similar role to the one occupied by elephants in Africa and Asia.
  5. The cultural significance of the Aldabra Giant Tortoise cannot be overlooked. These majestic creatures have long been revered by local communities and are deeply entrenched in folklore and traditional practices.
  6. The Giant tortoises of the Indian Ocean islands were an important source of food for sailors. These animals were once heavily hunted for their meat and shells which were used to make souvenirs and jewellery but now they are mainly used as tourist attractions.

In The Zoo

The Aldabra Giant Tortoise is a majestic creature that can be found in the zoo. These gentle giants are considered one of the largest tortoises in the world, with some individuals weighing over 500 pounds. 

Aldabra Giant Tortoises have a lifespan of up to 150 years, making them one of the longest-living animals on Earth. In captivity, they require plenty of space to roam and graze as they are herbivores. Zoos provide them with ample opportunities for exercise and ensure their diets consist of nutritious greens such as leafy vegetables, dark lettuce, and hay.

Visitors to zoos can observe these fascinating creatures up close and learn about their unique behaviours from dedicated zookeepers who care for them daily. One particular zoo that boasts an impressive collection of Aldabra giant tortoises is Taronga Zoo in Sydney, Australia. Another zoo that houses these amazing animals is located at San Diego Zoo Safari Park.

Classification And Evolution Of Aldabra Giant Tortoise

The classification of the Aldabra giant tortoise (Aldabrachelys gigantea) is a subject that continues to fascinate researchers and wildlife enthusiasts alike. This species belongs to the Testudinidae family and is recognized by its distinct shell pattern and large size. Evolutionarily speaking, these tortoises are believed to have diverged from their closest relatives in the Galapagos Islands millions of years ago, adapting to the unique environment of the Aldabra Atoll. One of the most distinctive features of the Aldabra giant tortoise is its long neck and large, domed shell, which protects predators.

In terms of evolution, these incredible creatures have adapted to their environment on the remote Aldabra Atoll in the Indian Ocean. With limited resources and isolation from other species, they have developed unique traits that help them survive in this harsh habitat. The classification of the Aldabra giant tortoise has undergone several changes over time due to advancements in genetic research, helping scientists better understand their evolutionary history.

Relationship With Humans

The relationship between humans and Aldabra giant tortoises has been long and varied. Tortoises were first discovered on the Aldabra Atoll by Portuguese sailors in 1505. The sailors killed hundreds of tortoises for food, oil and ship-building materials. In 1771 when French explorer Louis de Freycinet visited the Atoll, he found only 4 living tortoises.

So their relationship with humans has been long and complex. These animals were once heavily hunted for their meat and shells which were used to make souvenirs and jewellery but now they are mainly used as tourist attractions. Today, they are protected by law and their numbers have rebounded some but they remain vulnerable to poaching and habitat loss. The Seychelles government has even created a national park to protect these animals. They were used as transportation by sailors in the Indian Ocean and later became popular as pets. Today, they are still kept as pets by wealthy people all over the world but they are also found in many zoos.

Conservation Status Of Aldabra Giant Tortoise

The Aldabra giant tortoise is a critically endangered species with an estimated population of 100,000-300,000 individuals. The giant tortoise is listed as vulnerable by the IUCN. They are threatened by loss of habitat, poaching and climate changes. Despite their conservation status, the tortoises are still found in the wild today. They can be found on the islands of Aldabra Assumption, cosmoledo and Farquhar in Seychelles. Despite its critically endangered status, the tortoise is doing relatively well today. Thanks to effective conservation measures, the population has increased somewhat in recent years. Additionally, there are now several thousand captive individuals in zoos and private collections around the world. This gives hope that this magnificent creature may one day be saved from extinction.

linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram